h1::before {
	content:'一起来练习：';
}

p {
	color: orange;
}

a {
   color: red;
}

div p {
	color: green;
}

.title {
    color: purple;
}

#demo {
	color: olive;
}
h2 {
	color: brown;
}

#length {
	/*font-size: 72pt;*/
	font-size: 72pt;
	color: #ccc;
	color:rgba(100,100,90);
	font-family: '黑体'
	/*font-style:italic;*/
	font-weight；bolder;
}

